Sendo A={X|X é impar menor do que 20} B={y|y é primo e monor do que 25} e c ={ Z e N|5 <19} calcule

Resposta:
A={3,5,7,9,11,13,15,17,19}
B={2,3,5,7,11,13,17,19,23}
C={5,6,7,8,9,10,11,12,13,14,15,16,17,18}
a)
A∩C={5,7,9,11,13,15,17}
b)
B∩C={5,7,11,13,17}
c)
A-B={9,15}
d)
AUB={2,3,5,7,9,11,13,15,17,19,23}
AUB-C={2,3,19,23}